Béhoust, France · Saturday, April 18, 2026

Fixed Distance 50 mi

La Diagonale des Yvelines 80km

Race completed

80 km Distance

860 m Climbing

5.3 Grit · Challenging

48.8307° N, 1.7214° E © OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 11 m / km Fast & Flat. This course is relatively flat and fast. Ideal for PB attempts.

Time limit 12 hours 9:00 min/km average. Comfortable. Room to walk the climbs and stop at aid. Among the tightest 50 mi cut-offs we track. Measured against 471 races of the same distance. Cut-off calculator →

Field size ~104 Mid-sized. Company early, well spread out by halfway.

DUV results for the 2026 edition (80km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, April

Daytime high 15°C

Night low 5°C

Rainfall Mostly dry

Daylight 13 h 49 m of light

Regional 2001-2020 average for April — NASA POWER, grid elevation 116 m. Not a forecast.

Results history

Year	Race	Finishers	Men's winner	Women's winner
2026	80km	104	Jeremy Boulets · 06:42:33	Amandine Fillion · 09:01:46

15% of the 2026 field were women.

DUV results for the 2026 edition (80km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a fast & flat course. Expect fast, runnable sections where rhythm is key.

By UltraHub Expert

👟 gear

With trail terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert

Gear for this race

Chosen for 80 km of trail with 860 m of ascent.

Trail Running Shoes 80 km of trail — cushioning that is still there in the last quarter.
Race Nutrition 80 km of self-supported fuelling between aid stations.
Hydration Vests Flask capacity for 80 km, without the bounce.
Headlamps A 12 h limit puts you out there after dark.
GPS Watches Battery life first — a 80 km day outlasts most full-GPS modes.

Salomon

Ultra Glide 4

$159.95 ★★★★★ 4.6

Brooks

Catamount 3

RunRepeat found the Brooks Catamount 3 to have a cozier upper that enhances the overall fit, though breathability and durability could be better. iRunFar noted…

★★★★★ 4.5

Tailwind

Endurance Fuel

All-in-one calorie and electrolyte drink mix. 200 calories per serving.

$25 ★★★★★ 4.8

Salomon

ADV Skin 12

Industry-standard 12L race vest with front flask pockets and minimal bounce.

$180 ★★★★★ 4.8

Nitecore

UT32

Dual-beam trail running headlamp (1100 lumens) with spot and flood beams.

$100 ★★★★★ 4.5

Garmin

Enduro 3

Ultra-endurance GPS watch with solar charging and 300+ hour battery in GPS mode.

$900 ★★★★★ 4.8

All gear guides →

Overview

The Diagonale des Yvelines 80km, organised by AAA Aventure in Béhoust, France, is a trail race with 860 meters of elevation gain across 80 kilometers. This climb averages 10.8 meters per kilometer, making it a flatter 50-mile race than 74% of its peers.

With a 12-hour time limit, runners must maintain a pace faster than 9 minutes per kilometer. This cutoff is tighter than 84% of 50-mile races, leaving less margin for error or extended breaks. The single edition saw 104 finishers.

Similar races

Other 50 mi trail ultras, closest in distance first.